Ideal Weight Calculator
Healthy weight range for your height.
Your details
For adults. The estimates update as you type.
A rule of thumb only: small frame lowers and large frame raises the Hamwi result by 10%.
Average of the four formulas
57.7 kg
Formulas range from 56.4 to 59.8 kg. A healthy BMI at your height is 50.4–67.8 kg.
Formulas compared with the healthy BMI range
Each formula
| Formula | kg | lb |
|---|---|---|
| Devine (1974) | 56.9 | 125.5 |
| Robinson (1983) | 57.4 | 126.6 |
| Miller (1983) | 59.8 | 131.9 |
| Hamwi (1964) | 56.4 | 124.4 |
| Average | 57.7 | 127.1 |
These formulas were originally developed for medication dosing, not as health goals. Treat them as a rough guide.
How to Calculate Your Ideal Weight
The ideal weight calculator estimates a weight for your height using four well-known formulas: Devine, Robinson, Miller and Hamwi. It shows each result, their average and the range between them, and compares them with the healthy weight range based on BMI (18.5 to 24.9) and the weight at a BMI of 22. If you enter your current weight, it also shows how far you are from each.
Whether you think of it as a recommended weight calculator, a weight formula calculator or a way to compute your ideal weight, the aim is the same: put a number on what a typical formula suggests for your height, then use your own judgement and your GP's advice to decide what is right for you.
The Ideal Weight Formulas
Each weight formula takes your height in inches above 5 feet (60 inches) and returns a weight in kilograms.
Robinson: men 52 + 1.9 × in; women 49 + 1.7 × in
Miller: men 56.2 + 1.41 × in; women 53.1 + 1.36 × in
Hamwi: men 48 + 2.7 × in; women 45.5 + 2.2 × in
Here “in” means inches over 5 feet, so a height of 165 cm (64.96 inches) is 4.96. Frame size, if you choose it, adjusts only the Hamwi result by 10% as a rule of thumb.
BMI 22 weight = 22 × height (m)²
Worked Example: Female, 165 cm, Currently 70 kg
A woman is 165 cm tall, which is 64.96 inches or 4.96 inches over 5 feet. The formulas give 56.9 kg (Devine), 57.4 kg (Robinson), 59.8 kg (Miller) and 56.4 kg (Hamwi). The average is 57.7 kg, and the results span 56.4 to 59.8 kg.
The healthy BMI range for 165 cm is 50.4 to 67.8 kg, with a BMI of 22 at 59.9 kg. At 70 kg her BMI is 25.7 (overweight). That is 12.3 kg above the formula average, but only 2.2 kg above the top of the healthy BMI range. The formulas sit lower than the BMI range here because they were not designed as healthy-weight targets.
Where These Formulas Came From
These formulas were originally developed for medication dosing, not health goals. Devine's 1974 formula is usually credited as having been written to help estimate drug doses, and the others are alternative height-based estimates of the same kind. That history is why they are best treated as one rough reference point alongside the healthy BMI range, and why they do not account for muscle mass, age, ethnicity or body composition.
Ideal Weight vs Average Weight
People sometimes look for an average body weight calculator when they really want to know what is healthy for them. An average only describes a group, so being above or below it does not tell you whether your weight is healthy. A better starting point is the healthy BMI range for your height, combined with other measures such as waist circumference, and a conversation with your GP.
Frequently Asked Questions
- What is the formula for ideal weight?
- There is no single formula. The best known are Devine, Robinson, Miller and Hamwi, which each start from a base weight at 5 feet (152.4 cm) and add a set number of kilograms for every inch above it. For a woman, Devine is 45.5 kg + 2.3 kg per inch over 5 feet; for a man it is 50 kg + 2.3 kg per inch. The calculator above applies all four and shows the average.
- How do I compute ideal weight with a weight formula calculator?
- Enter your sex and height, and the calculator converts your height to inches over 5 feet and runs each formula. A weight formula calculator is only doing arithmetic, so you can check it by hand: for a woman of 165 cm, that is about 4.96 inches over 5 feet, which gives 45.5 + 2.3 × 4.96 = 56.9 kg with the Devine formula.
- Why do the Devine, Robinson, Miller and Hamwi results differ?
- They were derived from different data and give different weights per inch of height, so the results differ by a few kilograms at most heights. The gap tends to widen for very tall and very short people. That spread is a good reminder that an ideal weight is an estimate, not a precise target.
- What is a suggested or recommended weight for my height?
- Most health guidance uses the healthy BMI range of 18.5 to 24.9 rather than one number, because healthy weights vary between people. At 165 cm that range is roughly 50.4 to 67.8 kg. The calculator shows this range beside the formula results so you can see how they compare. Your GP can help you work out where in the range suits you.
- Is the average body weight the same as an ideal weight?
- No. An average describes what people in a group weigh, while an ideal or healthy weight is about what is likely to suit your height and health. The average body weight of a population can sit above or below a healthy range, so it should not be used as a target. This page does not show population averages for that reason.
- How do I calculate my desired body weight?
- Start with the healthy BMI range for your height, then think about what you can maintain in daily life, including your muscle mass, activity level and any medical advice you have received. Your desired weight is a personal goal, and it is generally best set with a GP or accredited practising dietitian. Gradual change is typically more sustainable than aiming for a particular number.
- Do I need to know my frame size?
- It is optional. Some versions of the Hamwi formula adjust the result by about 10% for a small or large frame, and the calculator offers that as a simple rule of thumb. There is no reliable way to measure frame size from home, so treat the adjustment as rough and do not read too much into it.
- Are these formulas accurate for short people or athletes?
- They are less reliable below about 5 feet (152.4 cm) because they were built around heights above that, and the calculator will flag this. They also ignore muscle, so a muscular person can weigh well above the formula results and still be healthy. They were originally developed for estimating medication doses, not as health goals.
- Does the calculator work in pounds and feet?
- Yes. Switch to imperial units to enter your height in feet and inches and your weight in pounds, and results are shown in pounds. Behind the scenes it converts to kilograms and centimetres using 1 lb = 0.45359237 kg and 1 inch = 2.54 cm. Australian health information generally uses kilograms, so metric is the default.